Fresh features from the #1 AI-enhanced learning platform.Try it free
Fresh features from the #1 AI-enhanced learning platformCrush your year with the magic of personalized studying.Try it free
Question

# What is the hydraulic grade line? How does it differ from the energy grade line? Under what conditions do both lines coincide with the free surface of a liquid?

Solution

Verified

(Hydraulic grade line) It is the line that is representing the sum of static pressure head and elevation head.

\begin{align*} &\frac{P}{\rho g} + z\\ \end{align*}

(Energy grade line) It represents the sum of static pressure , the dynamic pressure and elevation pressure heads.

\begin{align*} \frac{P}{\rho g} + \frac{V^2}{2 g} + z\\ \end{align*}

The difference between HGL and EGL is that at EGL - Energy grade line there is present dynamic pressure head expression.

Both of the lines are the same only when the velocity is equal to zero and the static pressure is also zero.

## Recommended textbook solutions

#### Fundamentals of Electric Circuits

6th EditionISBN: 9780078028229 (12 more)Charles Alexander, Matthew Sadiku
2,120 solutions

#### Physics for Scientists and Engineers: A Strategic Approach with Modern Physics

4th EditionISBN: 9780133942651 (4 more)Randall D. Knight
3,508 solutions